Electric vehicles (EV) driven by electric energy have been developed to prevent global warming and to prepare for the depletion of petroleum resources. The electric vehicles have also been introduced to public transportation. The electric vehicles are powered by electric energy, and an electricity storage function unit such as a storage battery provided in each of the electric vehicles is charged with electric energy. For example, when the electric vehicle is employed for a route bus, there is a method of charging the route bus once a day with electric energy allowing the route bus to run throughout the day, or a method of charging the route bus with electric energy when the route bus stops at a bus terminal or a bus stop, while the route bus is in operation.
In the method of charging the route bus only once a day with electric energy allowing the route bus to run throughout the day, the route bus needs to be installed with an electricity storage function unit capable of storing electric energy allowing the route bus to run throughout the day. Consequently, the size, the weight, and the cost of the electricity storage function unit will be increased. Hence, the method of charging the route bus with electric energy when the route bus stops at the bus terminal or the bus stop while the route bus is in operation can reduce the size, the weight, and the cost of the electricity storage function unit that is to be installed on the route bus, compared with the method of charging the route bus only once a day can. Moreover, travel distance of the route bus per unit amount of electric power is also increased.
To charge an electricity storage function unit of a route bus with electric energy, the crew of the route bus connects a cable of an external charger to a charging port of the route bus, and charges the electricity storage function unit of the route bus. With this method, when the route bus has stopped at the bus stop, the crew needs to step out of the route bus for a while, and perform an operation of connecting the cable of the external charger to the charging port and the like. Thus, charging cannot be completed in a short time. Consequently, a system of charging the electricity storage function unit using a pantograph and an overhead line while the crew is on board the route bus, such as a trolley bus, has been known.
However, even in this system, the crew of the route bus needs to perform an input operation of information to start or stop charging the electricity storage function unit, after the route bus has stopped. This may interfere with other services such as checking the safety of the bus stop, collecting bus fare from the passengers getting on or off the route bus, and the like. Thus, to complete charging in a short time and operate the bus on schedule, it has been demanded to save time and effort required for charging as much as possible.